corrosion control by inhibitor

Corrosion is the destructive result of chemical reaction between a metal or metal alloys and its environment.
Metal atoms in nature are present in chemical compounds (i.e. minerals) , the same amounts of energy needed to extract metals from their minerals are emitted during the corrosion chemical reaction, corrosion returns metal to its combined state in chemical compounds that are similar or even identical to minerals form which the metal were extracted.
Corrosion is defined in different ways, but the usual interpretation of the term is “an
attack on a metallic material by reaction with its environment”. The concept of corrosion can also be used in a broader sense, where this includes attack on nonmetallic materials, but such attacks are outside the scope of this book.
Corrosion of metallic materials can be divided into three main groups
1. Wet corrosion, where the corrosive environment is water with dissolved species.
The liquid is an electrolyte and the process is typically electrochemical.
2. Corrosion in other fluids such as fused salts and molten metals.
3. Dry corrosion, where the corrosive environment is a dry gas. Dry corrosion is also frequently called chemical corrosion and the best-known example is high temperature
corrosion.